fix: 恢复本地 Convex Auth 链路

- 修复 desktop 脚本在 Linux 下优先使用后端虚拟环境可执行文件
- 移除 Convex Auth 的本地密钥兜底，回到真实 deployment env
- 首页未登录时先跳转 /auth，避免根路由直接触发 workspace 初始化失败

scripts/desktop-local.js

@@ -22,7 +22,33 @@ const path = require("path");
 const rootDir = path.resolve(__dirname, "..");
 const backendDir = path.join(rootDir, "wolai-backend");
 
-const pythonBin = process.env.PYTHON_BIN || "python";
+function resolveBackendPython() {
+  const fromEnv = (process.env.PYTHON_BIN || "").trim();
+  if (fromEnv) return fromEnv;
+
+  const isWin = process.platform === "win32";
+  const candidates = isWin
+    ? [
+        path.join(backendDir, ".venv", "Scripts", "python.exe"),
+        path.join(backendDir, ".venv312", "Scripts", "python.exe"),
+        path.join(backendDir, "venv", "Scripts", "python.exe"),
+      ]
+    : [
+        path.join(backendDir, ".venv-linux", "bin", "python"),
+        path.join(backendDir, ".venv", "bin", "python"),
+        path.join(backendDir, "venv", "bin", "python"),
+      ];
+
+  for (const candidate of candidates) {
+    if (fs.existsSync(candidate)) {
+      return candidate;
+    }
+  }
+
+  return "python";
+}
+
+const pythonBin = resolveBackendPython();
 const dataDir = process.env.MNOTE_DATA_DIR || path.join(rootDir, "data-desktop-test");
 
 const backendCmd =